Tribological Properties of Composites Based on a UHMWPE Modified Borpolymer

— This paper presents the results of a study of polymer composite materials based on ultra-high molecular weight polyethylene (UHMWPE) modified with a borpolymer (BP). It has been established that the introduction of a BP into a polymer matrix affects the tribological properties. Thus, the wear resistance of composites with a content of 3–5 wt % BP increased by 2.4–6.0 times compared with the initial UHMWPE. The coefficient of friction of composites at a content of 0.2–3.0 wt % BP remains at the level of the initial UHMWPE. When the content is 5 wt % BP in the composite this leads to a decrease in the coefficient of friction by 25% relative to the original polymer. It was found that the introduction of BP into the polymer matrix increases the wear resistance by 6 times and reduces the friction coefficient by 25% relative to the initial UHMWPE. It is shown that with an increase in the BP content in the polymer matrix during tribocontact, a structural rearrangement of the surface layers occurs with the formation of a secondary structure. It has been established that at a low content of BP, the adhesive friction prevails, which is confirmed by the presence of sagging and protrusions on the friction surface. A study of the morphology of the friction surface showed that the formation of secondary structures results in smoothing the grooves. This indicates a decrease in the abrasive action of the steel counterbody on the polymer, which leads to a decrease in the friction coefficient. The research results can be used in the development of composite materials based on UHMWPE for tribological purposes, used for friction units of machinery and process equipment as plain bearings and sealing washers due to the low friction coefficient and the absence of abrasive action.